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43 views

My vector math seems to be off in this 2D simulation of a solar system

I intend to simulate gravitational acceleration on a 2D plane (simplified, no gravitational constant). My code is interpreted without any error in the console, but instead of having the two circles ...
2
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0answers
16 views

How to convert body coordinate from Sun reference frame to Earth reference frame?

I have the coordinates of a celestial body w.r.t. Sun , expressed as (x,y,z), at a given time. I need to move this coordinates into a reference frame centered on Earth center, but after reading dozens ...
3
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0answers
28 views

Did some Shuttle flights really have no spacesuits aboard? [duplicate]

According to this source, pages 378-382 and 406, there were no launch suits for Shuttle missions STS-5 through STS-33. Instead, crew literally wore shirtsleeves during launch and re-entry, plus anti-...
3
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0answers
48 views

Why does the Rutherford engine seem to ignite instantly?

A highlight of any Rocket Lab Electron launch is second stage ignition, seen from an impressive angle in this video from Flight 16: Notably ignition seems ...
2
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0answers
26 views

Can the bleed-off fuel in an open expander cycle be substituted for another liquid?

In all expander cycles, fuel is used as the working fluid to generate the pressure difference necessary to drive the pumps. This makes sense in a closed expander cycle as it'll eventually be used in ...
1
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1answer
31 views

What is the relation between chamber pressure and expansion ratio?

I've always assumed that the expansion ratio of an engine equaled the pressure inside the engine over the atmospheric pressure, but I'm not sure this is right, could someone check me on this?
1
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1answer
75 views

How many spacecraft orbiting the sun?

How many spacecraft have been sent in a heliocentric orbit in all history? By this, I mean spacecraft sent to stay in heliocentric orbit. The satellites orbiting planets or moons don't count.
1
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1answer
43 views

How should we point our SpaceX Starlink ground transceiver antennas?

I don't have one of course, but I see that the Starlink ground transceiver antennas are flat but "pointable" to some extent. I assume but don't know for sure that there's at least some kind ...
0
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0answers
10 views

Is the United Nations Outer Space Objects Index anything more than a clone of the Celestrak's Satcat? Is it even that, or less?

This looks like this answer because that's where I found this. Ars Technica's SpaceX Starlink engineers take questions in Reddit AMA—here are highlights included a reader poll when I viewed it, screen ...
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0answers
41 views

Out of 47,108 lines in the Satcat why are there exactly two lines with launch of the year of 000?

This looks like this answer because that's where I found this. Celestrak offers a copy of a Satcat from which a tabulation of space objects can be gleaned: https://celestrak.com/satcat/search.php ...
-3
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1answer
84 views

Did USA share Moon rocks with other countries on a permanent basis?

USA got some 400 kg of Moon rocks with Apollo program. Did they share rocks with other countries in form of permanent gifts? If yes, then which countries got such gift, and what information about ...
2
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1answer
54 views

What will happen to Chang’e 5 orbiter?

What will happen to the Chang’e 5 orbiter which will return the collected samples to earth? Will it burn up in the atmosphere like Hayabusa, or is an extented mission planned?
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1answer
47 views

Gravity assist from Jupiter if leaving Callisto?

If I spacecraft was leaving Callisto to return to Earth, would there by any situation where it would use a gravity assist from Jupiter to increase its velocity?
7
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1answer
1k views

What is the danger of creating micrometeorite clouds orbiting the Moon by constantly landing spacecrafts on its surface?

It is a well-known fact that when meteorite hits surface of the Moon, a part of debris can end up on Earth because the escape velocity for Moon is low - 2.38km/s. A similar effect can be achieved by ...
3
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0answers
45 views

What radar-trackable steel ball was thrown from the ISS before October 2015? [duplicate]

The question What kinds of things have been tossed out of the ISS? contains a now-rotted link to a YouTube video of a steel ball being thrown from the ISS for radar tracking tests. I'd sourced it from ...
2
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0answers
51 views

How could METI laser pulses be “brighter than the Sun”?

This Astronomy online course page The Search for Extraterrestrial Intelligence contains the following, about half-way down: However, in recent years, human engineers have learned how to make flashes ...
3
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1answer
82 views

Leaving the ISS orbit

Working on a project of sorts and I can't wrap my head around this at all., have a question regarding leaving the ISS orbit. If, let us say as an example, an astronaut jumped out of a capsule which ...
1
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0answers
23 views

Studies that identify the best frequencies for transmitting interstellar messages?

We are searching for extraterrestrial communications from other solar systems, and some consider sending them as well. Are there studies attempting to identify which wavelengths are best suited for ...
4
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0answers
55 views

Could a tank of water under the launch pad be used instead of a flame trench?

A flame trench is a massive expensive thing that needs constant repair. After each launch, concrete and steel suffer cracks, chips, melting etc., and require expensive, time consuming repair. Would it ...
5
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2answers
79 views

What is the thrust of Momentus' thrusters?

I understand that they have an interesting method of using microwaves to produce plasma from water. They claim to have a "high" thrust and "high" specific impulse. Their Isp ...
2
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2answers
111 views

Are we sending data for extraterrestrial SETI/METI?

The SETI project is trying to detect radio transmissions of aliens. Assuming the ET have their own SETI using very similar technology to ours, are we sending data for them to receive? If we are not ...
0
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0answers
43 views

What kind of technology is required for Alpha Centauri communication?

Let's assume we already colonised Alpha Centauri. What kind of technology we need in order to send and receive 1kbps? Radio satellite orbiting the sun? How much power, antenna size and solar panel ...
3
votes
1answer
90 views

Falcon 9's theoretical horizontal performance

Roughly how fast would Falcon 9 accelerate, and what would its payload's final speed be, if mounted horizontally on an ideal cart? Make simplifying assumptions as needed: massless frictionless cart, ...
3
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2answers
630 views

One mothership and many droneships concept for interplanetary travel

In sci-fi movies, like Independence Day, we find one big mothership flanked by many small droneships. Take-off and landing giant spaceship is technically difficult and dangerous. The landing surface ...
6
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2answers
161 views

Is there anything preventing an astronaut from opening their helmet and exposing themself to the vacuum of space?

Say an astronaut had some sort of psychotic break during a spacewalk, is there any mechanism or failsafe that would prevent the astronaut from opening their helmet and exposing themself to the vacuum ...
2
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1answer
30 views

Tutorial for orbits from TLE data

I've been looking for a new hobby, and have been reading some about satellite tracking. I was wondering if there was a good tutorial that walks through how to use TLE data. So far I have found ...
8
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2answers
669 views

US states with most space launches?

Some space launches are made from Florida, some from Texas, some from California and so on. Which US states and territories had the most orbital space launches in all space history? I mean launches ...
3
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0answers
36 views

How large an asteroid sample does hayabusa2 have?

As the title says, is it known how big, or massive, hayabusa2's sample is, due for Earth touchdown on 6th December? I have tried some basic internet research but found nothing on the anticipated ...
2
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0answers
35 views

What is the mass of the Electron rocket's battery pack?

I am trying to estimate battery weights for electric pump fed rockets of various sizes and wanted to use the electron rocket as data to validate my calculations. However I was unable to find the mass ...
1
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0answers
16 views

GMAT targeting - why targeting RMAG and DEC works while RadApo and INC doesn't?

The GMAT examples demonstrate targeting using this method for targeting a specific Apoapsis increase maneuver: Vary the prograde speed Apply Maneuver Propagate to the Apoapsis Achieve "the ...
1
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2answers
85 views

Orbital Chinese firework-cluster

I remember when I was younger I had heard this story about the Chinese using primitive fireworks, and even strapping them to a bamboo glider in an attempt to reach the moon. This story probably isn't ...
9
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6answers
2k views

Using water as a high density storable hydro-lox propellant

Hydro/lox is an excellent fuel choice and has been used in many engine/rockets with high ISP requirements, however, the two biggest drawbacks of the propellant are its density and boil-off. Could this ...
1
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1answer
41 views

What is/was legacy TLE ephemeris type 2? (TLE, line 1, column 63)

Wikipedia's Two-Line Element Set entry for line 1, column 63 (1.12) says: Ephemeris type (internal use only - always zero in distributed TLE data)13 13Celestrak Frequently Asked Questions: Two-Line ...
4
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1answer
66 views

Does the Proton-M have a launch termination system?

I was under the assumption that, in contrast to the oft-repeated "oh, those Russians", Protons actually do have launch termination systems which can be used to destroy the vehicle, akin to ...
22
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1answer
1k views

Identify these mission photos

My grandfather who was involved with the DFVLR (now DLR) had all sorts of space-memorabilia in his basement, including a roll of pictures I've found. Does anyone know what mission they are from and ...
1
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1answer
106 views

What is the Starship forward dome?

What is the Starship forward dome? How does it look like? What other parts are connected to it and what is it good for?
2
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0answers
41 views

Early geographically accurate drawings of Earth [migrated]

The first drawing—roughly passable* by modern standards—which Ī̲ am able to find is this pic from 1834 attributed to Henry De la Beche Image links to: https://www.abroadintheyard.com/timeline-of-...
3
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1answer
125 views

Geolocalizing photographs on astronomical bodies

In Are pictures taken from ISS geolocalized? I was considering photos taken on the Moon by astronauts. How can I determine a photographer's position and lens direction? And further, since there isn't ...
0
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0answers
37 views

Using the Clohessy-Wiltshire equation, what would be the expression for ' r '?

I'm looking for an expression for r. The difficulty I'm facing is simplifying the C-W equation
2
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0answers
29 views

Can Lorentz forces partially cancel centrifugal forces?

If we had a tidally stabilised skyhook (https://en.wikipedia.org/wiki/Space_tether#/media/File:Skyhooks.gif) with electric charge and with a vector of force aiming towards the center of the Earth, ...
1
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0answers
16 views

Long delay-doppler measurements on deep space craft; couldn't optical measurements be made intermittently, mixed with contacts to other spacecraft?

In this comment below Will future deep space optical communications “ground stations” actually be in space, or on the ground? in response to a discussion about ground stations being used for tracking ...
4
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0answers
56 views

What prompted NASA to establish a KSC SWAT Team?

Based on this question, it looks like KSC has not only its own police department (which is fairly common for large facilities, even things like universities) but also a SWAT team, which apparently was ...
1
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1answer
33 views

What is the use of the Gonets network?

What is the use of the Gonets satelites? Is ir for consumers, satellite phone or for govt institutions?
1
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1answer
40 views

How do space agencies choose arrival dates to planets (i.e. Mercury) from a gravity assist (i.e. Venus)?

Assuming I was looking for arrival opportunities from 2020 to 2030, how can I calculate the possible arrival dates to Mercury given a departure date from a gravity assist from Venus?
7
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3answers
627 views

Arecibo: Advantages of Giant Dish?

I'm sure all of you have heard about the recent events at the Arecibo observatory, and the controversial decision to close the facility. I've also heard that Arecibo is the second largest single ...
0
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1answer
48 views

When B is directly below A, as shown, what's B’s velocity (in vector notation) relative to A?

Spacecraft A and B are in coplanar circular orbits around the Earth. The orbital radii are as shown in the figure. (Not looking to use C-W equation. Just the equation describing relative velocity ...
12
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1answer
293 views

What was this strange design for the Man In Space Soonest program?

The following picture shows various spacecraft design proposals for the 1958 U.S. Air Force Man In Space Soonest program: The bottom row depicts various spaceplanes, which should not be a surprise ...
11
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3answers
2k views

Are pictures taken from ISS geolocalized?

I guess my question is "naive". I get from https://images-api.nasa.gov some pictures of Earth from ISS without any description (just the mission number) or pictures of crewmembers. Taken ...
6
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1answer
534 views

Are SpaceX launches from California going to retrograde orbits?

SpaceX has a launch site in Vandenberg Air Force Base, California. Will satellites launched from that place have a retrograde orbit?
6
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1answer
64 views

Has any research been done in deep-cold robotics?

I'm reading all kinds of things about mining water from the Permanently Shadowed Regions of the moon -- the bottoms of craters near the poles -- and I'm thinking Um, guys? It's 30 degrees Kelvin down ...

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